Harmonic frequency selector and amplifier circuit



Dec. l, 1931. R. H. woRRALL 1334233 HARMONIC FREQUENCY SELECTOR ANDAMPLIFIER CIRCUIT Filed Nov. v. 1927 l -l. Hm

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S11/Danica Patented Dec. 1, 1931 UNITED STATES PATENT' OFFICE ROBERT H.T-VOBBALL, OF WASHINGTON, DISTRICT O F COLUMBIA, ASSIGNOR, BY IIESNEASSIGNMENTS, TO FEDERAL TELEGRAPH COHPANY, A CORPORATION OF CALI- FORNIAHARHONIC FREQUENCY SELECTOR AND AMPLIFIER Application led November 7,1987. .Serial No. 281,590.

My invention relates broadly to signal transmission systems and moreparticularly to a circuit arrangement for a plezo electric crystalcontrolled-transmitter system.

One of the objects ofmy invention is to utilize the harmonic frequenciesof a piezo electric crystal by providing a circuit arrangement for thetransmission of signals at a selected frequency.

Another object of my invention'is to select a desired harmonic frequencyfrom a piezo 4 electric. crystal oscillator by providing a circuitarrangement for selecting this frequency and transferring the energy toa signal transmission circuit. p Still another object of my invention isto select and amplify a desired harmonic frequency of a piezo electriccrystal controlled oscillator by providing a practical circuitarrangement for selecting and amplifying this frequency for thetransmission of signals.

Other and further objects of my invention reside in the circuitarrangement for a piezo 'electric crystal controlled transmitter, as

more fully described in the specification here-- l inafter following byreference to the accomwill be seen that the crystal control circuitpanying drawings wherein:

Figure 1 is a diagrammatic circuit arrangement of the piezo electriccrystal controlled transmitter circuit of my invention illustrating theprinciples of my invention;

Fig. 2 shows a modified coupling circuit arrangement for the piezoelectric crystal controlled oscillatorand power amplifier circuit of myinvention; and Fig. 3 showsone of the circuits which I may employ in thepower amplifier and oscillator system for controlling regenerativeaction in the tube circuits of the transmitting system.

By reference to Fig. 1 of the drawings it consists of the following:electron tube 1, the quartz crystal 2. a grid leak 3, primary winding 4of transformer 5 and a by-pass condenser 6 connected in the propermanner to batteries 7 and 8. lCoupled to primary winding 4- of thecrystal circuit is the frequency selector and amplifier circuit 9 whichconsists of an inductancel 10 tuned by a variable 4,condenser 11, a gridcondenser 12, and

a grid leak 14 in the input circuit of power amplifier tube 15.Theoutput circuit includes a balancing condenser 16, a radio frequencychoke 17, a blocking condenser 18 and an inductance 19 tuned by thecondenser 20 connected to a transmitting-tube 15 and a power source inthe proper manner. The antenna circuit .21 may consist of any of themany medium of inductive coupling to the induc- 'types of'inductive ordirect coupled circuits tance 10, the circuit consisting of coil 10 andp condenser 11 constituting the grid circuit of the power amplifier. Thecircuit 9 may be tuned to any multiple of the crystal funda mental, andthe same multiple frequency amplified by tuning the plate circuit oftube 15 which includes the -20. The condenser 1 acts as a balancing con-1l 19 and the condenser denser, 'and a regeneration or degenerationcontrol, that is, the condenser 16 may also be used as a control deviceforoverning the excitation of the antenna 21. e grid circuit 9 may alsobe tuned to the crystal fundamental and any multiple of the fundamentalmay be amplified by tuning the plate, circuit. The

grid circuit may also be tuned to any multi le ofthe fundamental, andany multiple of t is multiple may be amplified in theyplate circuitpreviously described and transferred to other vamplifiers for furtherpower amplification and thence to any antenna or to the antenna. systemas shown at coil 22 and con- 1 denser 23.

This process of amplification may be contnued'to tubes of the largestpower through to the l trol between the output circuit of theoscillaries tor and the input circuit of the power amplifier. The platecircuit inductance 4 is provided with a slidable connection at 24 which.extends to coupling condenser 12. The opposite end of inductance 4 isconnected through condenser 25 with the opposite side lof the inputcircuit of. the power amplifier.V Tuning condenser 11 is connectedacross inductance 4 for facilitating the selection of a harmonicfrequency of cr stal 2.

Fig. 3 illustrates a m0 ified coupling circuit arrangement whichcontains the piezo electric crystal controlled oscillator and the poweramplifier,- whereby a harmonic frequency may be produced and radiatedfrom the antenna system. In the several modified circuits, I may employeither series or arallel feed for the plate supply system but orthepurpfosed of simplicity I have illustrated seee Among the advanta esarising out of the circuit arrangements o my invention, there is theability of the circuit system to develop weak harmonics in theinductance 4 and permit these 'harmonics to be transferred to a poweramplifier system and amplified for transmitting purposes. Thetransmitting circuits may be shifted from -one harmonic frequency toanother without touching or changing the piezo electric crystal 2. Theadvantage of the harmonic frequencies and selection of a particularfrequency may be effected through the medium of two electron tubes inthe circuit arrangements. shown, and the selected and lamplified.harmonic frequency is made available for transfer to any number of sta's of additional amplification for placing t e' energy in propercondition for radiation and ton of sials. ile I have described myinvention in certain preferred embodiments, I desire that it beunderstood that modifications of my invention may be made and that nolimitations upon my invention are intended other than are imposed by thescope of the appended claims.

What I claim as new and desire to secure b {Jetters Patent of the UnitedStates is as fo ows: I

1. A frequency selector and amplification system com rising an electrontube for nerating hig frequency oscillations, a piezo ,electric crystalconnected to said electron i 'tube for stabilizing the frequency of saidelectron tube, circuits connected tothe output of 5 said electron tubefor selecting a harmonie fre uency ofthe fundamentalfrequency of saipiezo electric c stal, and connections Abetween the output; vcircuit ofsaid electron tube and yanother electron'tube. effecting an increase inamplitude'iof the harmonic frequency thus selected.

2. n a transmitter system,'the combination of a signal transmissioncircuit, a piezo electric crystal element, an electron tube having inputand output circuits, the input circuit of said electron tube connectedto said piezo electric crystal element, saidv electron tube having meansconnected .into its output circuit for selectivel and independentlysustaining a plurality o harmonics of the fundamental frequency of saidpiezo electric crystal element, an amplification system, a tuned circuitcou ling said amplification system with said a orementioned means andadjustable to selectively amplify any one of the harmonic frequencies ofsaid piezo electric crystal element selected and sustained by saidaforementioned means, and connections between said amplification systemfand said transmission circuit for 'impressing the selected' harmonicfrequencies of increased amplitude upon said transmission circuit. L

ROBERT I-I.l WORRALL.

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